AI Article Synopsis
- The Hückel Molecular Orbital (HMO) method was used to analyze the stability of various isomers of conjugated acyclic polyenes up to 7 carbon atoms by examining their π-electron energies.
- The mean length of conjugation helps predict the stability order among the isomers, with the Hosoya-index providing even better accuracy.
- A systematic diagram was created to illustrate the genealogy of these isomers, categorizing their stability changes based on vinyl addition methods and the concept of "horn growing" for further exploration of polyene radicals and specific cyclic polyenes.
Article Abstract
Based on the total π-electron energies s of Hückel Molecular Orbital (HMO) method for all the possible isomers of conjugated acyclic polyenes (C₂H₂) up to = 7, the structure-stability relation of the possible isomers was analyzed. It was shown that the mean length of conjugation can roughly predict the ordering of stability among isomers, while the -index, or Hosoya-index, can almost perfectly reproduce their stability. Further, the genealogy of the conjugated acyclic polyene family was obtained by drawing systematic diagrams connecting these isomers of different , and governed by several simple rules. Namely, the stability change of a given isomer in the genealogy connecting and + 1 polyenes can be classified into three different modes of vinyl addition (elongation, inner and outer branching) and horn growing, i.e., substitution of -HC=CH- moiety with -HC(=CH₂)-C(=CH₂)H-. By using the -index, we can extend this type of discussion to polyene radicals and even to "cross-conjugated" cyclic polyenes containing only one odd-membered cycle, such as radialene and fulvene.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6152726 | PMC |
| http://dx.doi.org/10.3390/molecules22060896 | DOI Listing |
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